// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_REQUEST_HANDLE_H_
#define CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_REQUEST_HANDLE_H_

#include "base/compiler_specific.h"
#include "base/memory/weak_ptr.h"
#include "content/browser/download/download_resource_handler.h"
#include "content/common/content_export.h"
#include "content/public/browser/resource_request_info.h"

namespace content {
class DownloadManager;
class WebContents;

// A handle used by the download system for operations on the URLRequest
// or objects conditional on it (e.g. WebContentsImpl).
// This class needs to be copyable, so we can pass it across threads and not
// worry about lifetime or const-ness.
//
// DownloadRequestHandleInterface is defined for mocking purposes.
class CONTENT_EXPORT DownloadRequestHandleInterface {
public:
    virtual ~DownloadRequestHandleInterface();

    // These functions must be called on the UI thread.
    virtual WebContents* GetWebContents() const = 0;
    virtual DownloadManager* GetDownloadManager() const = 0;

    // Pauses or resumes the matching URL request.
    virtual void PauseRequest() const = 0;
    virtual void ResumeRequest() const = 0;

    // Cancels the request.
    virtual void CancelRequest() const = 0;
};

class CONTENT_EXPORT DownloadRequestHandle
    : public DownloadRequestHandleInterface {
public:
    DownloadRequestHandle(const DownloadRequestHandle& other);
    ~DownloadRequestHandle() override;

    // Create a null DownloadRequestHandle: getters will return null, and
    // all actions are no-ops.
    // TODO(rdsmith): Ideally, actions would be forbidden rather than
    // no-ops, to confirm that no non-testing code actually uses
    // a null DownloadRequestHandle.  But for now, we need the no-op
    // behavior for unit tests.  Long-term, this should be fixed by
    // allowing mocking of ResourceDispatcherHost in unit tests.
    DownloadRequestHandle();

    DownloadRequestHandle(const base::WeakPtr<DownloadResourceHandler>& handler,
        const content::ResourceRequestInfo::WebContentsGetter&
            web_contents_getter);

    // Implement DownloadRequestHandleInterface interface.
    WebContents* GetWebContents() const override;
    DownloadManager* GetDownloadManager() const override;
    void PauseRequest() const override;
    void ResumeRequest() const override;
    void CancelRequest() const override;

private:
    base::WeakPtr<DownloadResourceHandler> handler_;
    content::ResourceRequestInfo::WebContentsGetter web_contents_getter_;
};

} // namespace content

#endif // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_REQUEST_HANDLE_H_
